Magazine type hot-air stove for burning solid fuel



April 22, 1952 K. A. NlERMEYER 2,593,690

MAGAZINE TYPE HOT-AIR STOVE FOR BURNING SOLID FUEL 2 SHEETSw-SHEET 1 Filed May 7, 1947 ATTORNEY A ril 22, 1952 MAGAZINE TYPE Filed May 7, 1947 K. A. NIERMEYER 2,593,690

HOTAIR STOVE FOR BURNING SOLID FUEL 2 SHEETS-SHEET 2 KA- NIERME YER WM ATTORNEY Patented Apr. 22, 1952 E is:

urn

MAGAZINE TYPE HOT-AIR STOVE FOR BURNING SOLID FUEL Karel A. Niermeyer, Leeuwarden, Netherlands Application May 7, 1947, Serial No. 746,551 In the Netherlands May 22, 1939 Section 1, Public Law 690, August 8, 1946 Patent expires May 22, 1959 1 Claim. 1

- vertically along the body of the stove must deflect laterally and therefore is hindered in its movement.

The invention has for its object to improve a stove of this kind in such a manner that the circulation of the air encounters the least possible resistance. With this object in view the gas circulation box according to the invention surrounds the stove body also at the rear and leaves an air channel with respect to the body opening above the filling space into a chamber provided at its upper side with one or more apertures through which the air escapes in vertical direction. With said construction of the circulation box the air rises upwards both at the side wall and at the rear of the stove body between the circulation box and is concentrated in the chamber above the stove body to a dense stream ascending vertically in the room. The air thus encounters the least possible resistance so that its rising power is fully maintained and a powerful air circulation is secured.

In a stove provided with a fuel reservoir which is wholly or partly surrounded by a jacket forming an air channel said latter according to the invention may be employed for promoting the air circulation in an efiicient manner. To this end said air channel at the upper end of the fuel reservoir opens into the channel left by the gas circulation-box with respect to the stove body and the jacket of the fuel reservoir at its rear is provided with an inlet nozzle having its mouth directed downwards. With said embodiment the air also in the jacket of the fuel reservoir rises vertically nearly without deflection so that the flow of air between the gas circulation box and the stove body and the flow of air through the jacket of the fuel reservoir will further each other whereby the circulation of the air is still increased.

In order to make the invention more clearly understood one embodiment thereof is illustrated by way of example in the accompanying drawing, in which Fig. 1 shows a vertical section through the stove.

Fig. 2 is a section of the stove taken along the line II-II in Fig. 1.

The filling opening of the fuel reservoir I is closed by a flap 2. The fuel falling'down out of the reservoir I forms in the fire box 3 a circular truncated cone which in the drawing is indicated by a dash and dotted line i. The bottom of the fire box is formed by a grate 5 below which an ash guide 5 is provided which ensures that all ash falling down through the grate is received in the tray 1.

The upper portion of the stove body i2 is surrounded by a circulation box 13, for the flue gases which on either side is connected at M to the combustion chamber and is supported on projections 23 at the top of the body l'2. As particularly appears from Fig. 2 the circulation box l3 is bent over the top of the stove body and forms a guide wall for the air rising along the body [2 according to the arrows a so that said air ascends in a powerful flow which is heated at the hot walls of the box. The air channel 2:3 formed between the circulation box l3 and the stove body I2 is widened in upward direction, see Fig. 1.

The fuel reservoir is surrounded by a jacket so that an air channel 25 is formed, in which the air is admitted through an aperture in the outer wall at the rear of the stove. In order to have the air entering the air channel with the least possible resistance the jacket is provided with an inlet nozzle 9 which is gradually contracted and the mouth of which is directed downwards. The air entering the jacket of the fuel reservoir leaves it through two sickle-shaped slots it which in forward direction are gradually widened and the air flows into the chamber ll according to the arrows b and joins the air stream ascending along the circulation box i3 according to the arrows at so that an injector action is obtained which materially furthers the air circulation. As the outermost air stream takes up heat both from the stove body l2 and from the inner wall of the circulation box is good efficiency is ensured. As further the inlet nozzle 9 gradually terminates into the wall 8 of the fuel reservoir l and the air channel 25 opens with large slots H} in the chamber II the air from the mouth of the nozzle 9 rises with very little resistance so that a powerful flow is secured.

The air leaving the chamber [I may be used for cooking purposes as it is heated to a high temperature. To this end a grid is provided above the chamber II which is covered by a cover It. The stove body I2 is surrounded by an outer casing 26.

With the embodiment shown in the drawing the air of combustion enters at the bottom 22 of the body l2. To this end a series of slots I1 is provided in the bottom 22 the section area of which may be controlled by a slide valve l8 which runs in guides IS. The ash-tray I is therefore not directly supported on the bottom 22 but on an auxiliary bottom 20 which leaves passages 2| (Fig. 2) for the ascending air. With this construction the air of combustion is preheated at the bottom 20 and at the ash tray.

It is to be noted that the invention is not restricted to the above described embodiment as various modifications may be provided. Thus the stove body at its outer side may be provided with vertical fins in order to further the transfer of heat to the air ascending along the body. The gas circulation box may also be extended further downwards and a bafiie may be provided in the box for deflecting the flue gases downwards.

, What I claim is:

A stove of the character described, comprising a main stove body including a fuel reservoir, a fire box, a grate and an ash receiving tray, a portion of said body forming a combustion chamber, a hot gas circulation double-walled hood surrounding thesides and rear of and having its inner walls bent over the top of said combustion chamber, means forming an air collecting chamber above the top of said main body and having an air escape aperture lying in a horizontal plane at the top of said collecting chamber opposite the top of the main body, means forming a gas flow connection between said combustion chamber and said gas circulation hood, said hood, being spaced from said body to form a first air flow channel along said body to said collecting chamber, said fuel reservoir extending into said combustion chamber, and a jacket on said fuel reservoir forming a second air flow channel communicating at its upper end portion with said first air flow channel and having a downwardlydirected inlet nozzle at the lower rear portion thereof. I KAREL A. NIERMEYER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 108,733 Sexton, et a1. Oct. 25, 1870 148,668 Chelius Mar. 17, 1874 1,490,135 Skinner Apr. 15, 1924 1,700,911 Smith Feb. 5, 1929 1,915,688 Miller, et a1 June 27, 1933 2,114,584 Aunger Apr. 19, 1938 2,175,832 Demarcay Oct. 10, 1939 

